Google demonstrated Google Assistant AI making telephone calls. It sounded very natural, and seemed to handle the call well. It's noted later in the video that there are lots of calls that didn't go so well, so it's a shame they didn't appear to play those.
“The amazing thing is that Assistant can actually understand the nuances of conversation,” he said. “We’ve been working on this technology for many years. It’s called Google Duplex.”
Play the video on the story and you'll see what I mean.
From a technical perspective, this is excellent, but for the future, this might just be another worrying trend.
Personally, if I realised it was an AI I don't yet know how i'd handle it as i'd be talking to a machine. OTOH, some of the phone spammers working to a script sound just like machines. lol